(Probably?) oncidium going pale and drying up

[narquelie19]

Thanks everyone - really grateful to get so many helpful replies. I'll try to answer all the questions and points:

* When I repotted it (so about 3 months ago), I got rid of the roots that looked dark brown, mushy, and came apart as soon as I (very very) gently pulled at them. Did I do the wrong thing?

* How do I stake an orchid like this? What part of the orchid would I tie to the stake?

* The point about condensation on the sides of the pot is really good - I may have underwatered because of that.

* It's definitely not getting too much sun (possibly the opposite), as it's in a room with one west-facing window (plus winter in the UK means limited sunlight anyway). It's possible that the air is not humid enough? My little thermometer thing shows 40% RH.

* I'm a bit confused on the advice I've had re what to repot it in:

Originally Posted by Orchidtinkerer

So go for medium and fine and use a smaller pot. The more substrate is around the orchid the less the pot can breathe.

[...]

I have mentioned how important the substrate is because it is generally not overwatering that causes roots to rot. Like it is very difficult to overwater a bareroot orchid for example. What causes roots to rot is when they get too little air, they need to be able to exhange gasses on a daily basis, compact susbtrate that stays too wet prevents this air exchange which leads to roots rotting.

Wouldn't fine bark be more compact and thus not have enough air flow?

Thanks again!

[Steve83]

Yes, compaction of finer media restricts airflow. But, wicking action (or lack thereof) of the media, pot material/holes, how often you're water boarding them, and airflow in the growing area all play factors as well. Not to mention, the plant variety itself.


Do you have a fan in the growing area? You'd be surprised at how much of a difference that can make.

[Roberta]

Those floppy growths can be tied to individual stakes just to hold them vertically.
Another approach would be to put, perhaps, 3 of them in a triangle, then use wire or plant ties to sort of make a fence with the floppy growths inside, holding them up.